The accuracies of the models for each isoform when tested on independent test sets are shown below:
Results of the P450 Regioselectivity Models on independent test sets
| Isoform | N * | All metabolites correctly predicted ** | At least one metabolite correctly predicted | Incorrect |
| CYP3A4 | 168 | 68% | 17% | 15% |
| CYP2D6 | 188 | 75% | 12% | 13% |
| CYP2C9 | 139 | 72% | 12% | 16% |
* N = number of compounds in independent test set.
** Observed metabolites in the top 3 predicted sites or >10% predicted metabolism.
Only 14 of the 22 molecules that form the top 20 drugs in this study are metabolised by Cytochrome P450 enzymes. These 14 drugs produce a total of 22 major metabolites of which 19 are correctly identified (86%), and a total of 6 minor metabolites of which 5 are correctly identified (83%). The results of the study are summarised below.
Summary of Results for Top20 Drugs* Using Regioselectivity Models
| Rank | Active | Indication | Major Metabolising Enzymes | Metabolites Correctly Identified | |||
| 3A4 | 2D6 | 2C9 | Other | ||||
| 1 | Atorvastatin | Elevated cholesterol | x | 3A5 | 2/2 | ||
| 2 | Simvastatin | Elevated cholesterol | x | 3A5,2C8 | 2/3 | ||
| 3 | Salmeterol xinatoate | Asthma | x | 1/1 | |||
| 3 | Fluticason propionate | Asthma | x | 1/1 | |||
| 5 | Olanzapine | Psychosis/schizophrenia | x | 1A2,MAO | 2/2 | ||
| 6 | Esomeprazole | Gastrointestinal disorders | x | 2C19 | 4/4 | ||
| 8 | Sertraline | Depression | x | 1/1 | |||
| 9 | Venlafaxine | Depression | x | x | 3/3 | ||
| 11 | Celecoxib | Arthritis | x | 1/1 | |||
| 13 | Valsartan | Hypertension | x | 1/1 | |||
| 14 | Risperidone | Psychosis/schizophrenia | x | 0/2 | |||
| 15 | Losartan | Hypertension | x | x | 1/1 | ||
| 18 | Montelukast | Asthma | x | x | 3/4 | ||
| 20 | Lansoprazole | Gastrointestinal disorders | x | x | 2C19 | 2/2 | |
*By sales for 2004. Source: Med. Ad. News May 2005.
